Conventionally, various kinds of moving stands, which can telescopically accommodate and protract a plurality of stages of decks horizontally arranged, have been proposed. They are, in most cases, capable of providing a plurality of chairs on each of the decks, thereby enabling a predetermined number of spectators, etc. to sit on the moving stand.
Then, in such a moving stand, accommodating the respective decks when they are unused requires causing each of the chairs to take the folded attitude forward, which requires causing each of the chairs to take the raised attitude, enabling the spectators to sit thereon, when the moving stand is used.
Therefore, as described in JP-A-62-201109, the applicant has proposed an automatic chair-raising and folding apparatus which is capable of automatically raising and folding chairs without using special power sources, with the protracting and accommodating operation of decks.
In this apparatus, a main part of which is shown in a side view of FIG. 1, a bed frame 103 is disposed on a deck 101, and a chair leg 105 is arranged on the bed frame 103 raisably and foldably. A three-pronged lock ring 111 has a locking and unlocking roller 107 as a weight, and a hook portion 109 at a lower pronged portion thereof. The leg 105 is connected with the three-pronged lock ring 111 with a front end penetrating shaft 113 as a fulcrum in such a manner that the roller 107 can move downward. Disposed on a back side of the leg 105 is a locking angle 115 for holding the leg 105 in the raised state due to the engagement with the hook portion 109 of the lock ring 111 with the roller 107 moving downward; therefore, when the deck 101 is retreated, the roller 107 abuts against the upper stage-side deck 117, thereby causing the hook portion 109 and the locking angle 115 to be released and disengaged from each other. As a result, protracting each of the decks causes the chairs to be automatically raised, and accommodating each of the decks causes the chairs to be automatically folded forward.
The proposed technique has, however, disadvantages that the construction of the apparatus becomes complicated, and further the weight of the apparatus, in its turn the weight of each stage of the decks is increased.
Also, when the moving stage is used with only intermediate stages of the decks, i.e. the lowest two stages of the decks out of six stages of the decks protracted, suitably seating on the chairs of the second deck, i.e. raising up backrests of the chairs, disposed on the second deck, above a passage B of the third deck A requires causing the third deck A also to take the protracted attitude. According to the proposed technique, protracting the third deck A causes the chairs disposed on the deck to necessarily take the raised attitude; therefore, there is a disadvantage, from the viewpoint of spectator-guide-countermeasure, that the spectators, etc. are required to be prevented from entering into the passage B by taking a suitable countermeasure of surely preventing the spectators from using the chairs C, e.g. roping off, or fencing in the place, or guiding the spectators, etc. by guides, guards, etc.
Moreover, in such a case, when the chairs C on the third deck A are free to be used, the backrests of the chairs C interfere with the upper stage-side accommodating deck above the deck A, thereby disabling the backrests to be sufficiently folded rearward, which disables the seat to take a satisfactory free attitude. Therefore, not only the comparability to sit on becomes bad, but also unexpected forces act on the chairs C, which possibly may cause the chairs C to get out of order, etc.
Also, in the proposed technique, automatic raising and reversing apparatuses are independently arranged for respective chairs on the same deck. For example, as exemplified in FIG. 3, so long as the first stage deck D retreats during the protracted decks are accommodated while being inclined in the fore and rear direction, i.e. in the advancing and retreating direction, under the influence of the condition, such as unevenness of the floor on which the moving stand is disposed, and so on, even when the chairs disposed on one end portion of the deck D in the longitudinal direction, in its turn the leg 105 of the chair is unlocked, and hence the leg 105 starts to fold, the legs 105 of the other chairs may be still in the locked condition. Especially when a plurality of chairs disposed on the deck D are so-called connected chairs which are connected to one another, the occurrence of the above-mentioned state provides a problem that the connected chairs undergo an unexpected large torsional external force, etc. not only thereby causing the connected chairs to be damaged worst of all, but also thereby causing the deck D to be retreated to disable the other chairs to be smoothly unlocked. The same is true of the advancing and retreating direction-wise inclination of the deck when the specified deck is advanced to thereby be protracted.
The present invention has been made as a result of investigating the subject of solving the above-mentioned problem included in the above proposed technique. It is therefore an object of the present invention to provide a chair-raising and folding construction for a moving stand, which is capable of precluding the possibility of increasing the weight of decks, and effectively preventing spectators, etc. for entering into a surplus stage of decks which are, when lower decks are protracted for use, obliged to be protracted to a rear side of the lower decks, and to provide a chair-raising and folding construction for a moving stand, which is capable of, even if a plurality of chairs disposed on the deck are connected to one another, not only raising but also folding smoothly and surely the connected chairs irrespective of the retracted attitude of the deck, and also of satisfactorily preventing the connected charts from receiving a torsional force, etc.